You're equivocating. I am not talking about genre simulation, I am talking about simulating physics within a genre. You said "world-simulation" but you didn't say what world. Simulation does not have to be realistical at all; if it were, anything with dragons and magic would already be on its way out the door.
I agree that you can simulate things that aren't reality. But if you make "simulationism" conditional, and allow its use for simulation of a genre, almost any game mechanic suddenly becomes simulationist.
Let's take your discussion of Hit Points...
Conan, like most action heroes, can withstand a lot of combat. High hit points simulate Conan getting hacked at by brigands and walking away with only flesh wounds and bruises.
OK - for what it's worth, I agree. That's exactly what hit points mean.
Now, let's talk Minions, everyone's favorite, using your same argument.
"The orc rabble, like most mooks in action movies, can't last long in combat. 1 HP simulates the orc getting put out of a fight as soon as a hero does anything to them."
All of a sudden, minions are simulationist. I love minions, but I don't know that I'm comfortable with that categorization.
Now, we can move on to solos - the 4e creatures with 4x HPs.
"A Red Dragon, like most big, epic fantasy monsters, has a lot more staying power than your average hero, being able to take on whole armies. High HPs simulate the dragon's staying power, and ability to face down hordes of enemies and perhaps surviving."
Or, my example of encounter powers...
"Action heroes usually have a few signature moves that they can do in a fight, but which they don't use over and over again - even if it's clearly the most effective thing they could do. Encounter (and Daily) powers simulate the genre by giving characters these signature moves, without allowing them to do them repeatedly."
Once you broaden the term "simulationist" enough, everything is potentially simulationist. I think that the common usage among gamers, though, carries an implication that game rules should be expressions of in-world physics - and not expressions of genre conventions. Which is why, IMO, hit points should never be considered simulationist at all.
-O